On-line Laboratory Manual for First-Year Chemistry
James M. McCormick
Department of Chemistry
November 10, 2008
Introduction
Traditional laboratory manuals are very linear in the manner in which they deliver information to the student. In part, this is due to the nature of the material, such as where new concepts build on previously learned ones, or where students are learning skills that must be done in a particular order. However, to a great extent the linear information delivery results from the inherent linearity of the printed word. This can be a hindrance to learning, because learning is not necessarily a linear process. For example, when reading new material and encountering an unfamiliar concept, it is typical for a reader to stop and look for its definition, either in nearby text or in a glossary. This process can be time-consuming and interrupts information transfer. An on-line document can streamline this process by having on-demand information simply a mouse-click away. This also means that a laboratory exercise can be much more concise, modeling that of actual scientific papers, but with assistance available to students who need it through links to other documents or pop-ups. In the same manner, supplemental material, either locally or externally produced, can be provided to students who want to learn more about a particular subject. Finally, an on-line laboratory manual’s main advantage over the printed word is that video and audio can be used to present information.
Project Description
The laboratory manual for the first-year chemistry sequence (CHEM 120-CHEM 121) is a continuing effort to use the strengths of on-line documents to further student learning and to meet the goals set forth for the laboratory component of these courses. It is part of, and overlaps with, the larger ChemLab.truman web site which is being developed as a central repository of information common to all Truman chemistry laboratory courses and as a portal to individual course web pages.
In its current incarnation, the site features a fairly spartan main body with links to the individual exercises (note on the Environmental Chemistry exercise). Each exercise follows the standard format for a chemistry research publication, to begin to familiarize students with this style. The basic information is given in the exercise with links to information covered in previous or multiple exercises. When additional assistance is available a Help Me link is displayed, while the More Info link directs students to additional information on a topic. The 
icon is displayed to alert students to important safety information for that exercise. These links lead to either resizable pop-up windows (Java scripts) or other pages that open in a new window. Students are free to follow any, or all, of these links, as they see fit. And in this way students can customize exercises to fit their particular needs.
How this approach has been realized is shown in the CHEM 120 exercise Preparation of Alum. Over a three-week period students first synthesize the alum and then perform a series of chemical analyses on their material in weeks two and three. This is a challenging exercise because the students learn several laboratory techniques, including how to use a spectrometer, and must then apply what they have learned in lecture about stoichiometry and solution preparation. The procedure is fairly detailed because it is the second exercise of the semester (note on procedures), but there are still links in the procedure to assist the students. In particular, there is a link that describes the spectrometer that they will be using several times in the semester. With this link a long, distracting digression on spectrometer operation in the middle of the procedure is avoided. A student can read the entire procedure and then come back to get details on the spectrometer and its operation, which are not necessary to understand what he or she is trying to accomplish.
In the Preparation of Alum exercise the main use of the Help Me links is in the Results and Analysis section. Here the links are used to direct students to help on statistics (covered in lab the previous week) and to provide help on the calculations necessary to find the amount of aluminum in their sample. This latter point is particularly challenging for students, and so a worked example is provided. This example takes the students step-by-step through the calculation, providing them with the opportunity to set up and solve each calculation. The answer is given so students know whether they did the calculation correctly, and the correctly set up calculation is available through a Help Me link. In this way students are guided through the process, much in the same way they would be led by an experienced teacher.
Summary and Future Work
The laboratory manual for the first-year chemistry sequence attempts to use the strengths of web pages to enhance content delivery to students. While it has been well-received, this project is still very much a work in progress with work progressing on several fronts. The first is to the site’s aesthetic appeal and readability, where informal feedback from students and colleagues are being incorporated as the site is revised each semester. The primary area in which changes are being made is to the site’s content. Based on student feedback and suggestions from colleagues, additional topics where students are prone to have problems are being identified. Help Me links will be added to address these areas. The guided examples will also be improved. Currently the guided examples rely on the students to attempt the problem before looking at the solution. There is the obvious temptation for a student to simply look at the solution and never attempt the problem. Others have solved this problem by using what might be called “incremental help.” In incremental help a student enters the solution to a problem, and then based on this answer, a possible course of action would be suggested. The student can then try again, and can continue to try until they get the correct answer. This does away with the opportunity to obtain the answer without doing any work, and as such is a much better pedagogical tool than what is currently available. However, this level of guided help is difficult and time-consuming to program because the programmer must anticipate every mistake a student can make. The final area of content being examined is where and how best to include video and audio. The primary consideration here is balancing information transfer with bandwidth considerations. It is likely that only a few short, key procedures will be made available on a trial basis with their pedagogical utility being constantly evaluated.
Acknowledgements
The following colleagues have contributed to the on-line laboratory manual’s development by writing exercises, testing exercises or proofreading the final documents: Barbara Kramer, David McCurdy, Brian Lamp, Maria Nagan, Vaughan Pultz, Anne Moody, David Wohlers, Russ Baughman, Dawood Afzal, and Vinita Dew. Special thanks go to Heather Ervin, chemistry technician for CHEM 120/121, who helped develop the experiments and whose assistance in all aspects of creating this resource and making the laboratory function was invaluable.